A. Closed Loop Catheters
The prior art has included numerous “closed loop” catheters having closed loop fluid flow circuits formed within the catheter. Examples of such closed loop catheters include various types of catheters that have a) a first lumen through which a fluid may flow into the catheter body and b) a second lumen through which fluid that has entered the catheter body through the first lumen may subsequently flow out of the catheter body. In some instances, a reservoir (e.g., chamber, vesicle, collector, space, etc.) may be formed on or within the catheter in fluid communication with the fist and second lumens such that fluid infused through the first lumen may collect within the reservoir and may subsequently flow out of the reservoir through the second lumen. Also, in some instances, the reservoir may have one or more flexible wall(s) and may be inflatable such that the reservoir expands when filled with fluid and collapses when fluid is evacuated from the reservoir. Examples of expandable reservoirs include various types of balloons including those which are elastic as well as those that are non-compliant and/or heat exchangers that may be formed on or in a catheter.
One specific type of closed loop catheter is an endovascular heat exchange catheter that may be inserted into a patient's blood vessel and used to heat or cool the blood flowing through that blood vessel and, hence, all or a portion of the patient's body. In these endovascular heat exchange catheters heated or cooled heat transfer fluid (e.g., saline solution) is circulated though a closed loop circuit. The closed loop circuit may include an expandable (e.g., inflatable) heat exchanger (e.g., a heat exchange balloon) that has a collapsed configuration when uninflated and an expanded configuration when inflated. Typically, endovascular heat exchange catheters that have expandable (e.g., inflatable) heat exchangers are inserted into the patient's vasculature through a small introducer or puncture tract while the heat exchanger is in its collapsed (e.g., uninflated) configuration. Thereafter, heat transfer fluid is circulated through the heat exchanger, causing it to assume its expanded (e.g., inflated) configuration. After the procedure has been completed, it is generally desirable to fully deflate the heat exchanger before attempting to reposition or remove heat exchange catheter from the patient's body to facilitate its passage through the relatively small diameter introducer/puncture site and to avoid possible damage to the patient's blood vessels. To accomplish such deflation of the heat exchanger, it may be desirable to apply negative pressure to the fluid lumen(s) of the catheter to ensure that the heat exchanger is fully deflated and in its fully collapsed configuration. Examples of such endovascular heat exchange catheters and related apparatus include those described in U.S. Pat. No. 5,486,208 (Ginsburg), PCT International Publication WO 00/10494 (Machold et al.), U.S. Pat. No. 6,264,679 (Keller et al.), PCT International Publication Nos. WO-00/10494 (Radiant Medical, Inc.) and WO 01/58397 (Radiant Medical, Inc.), all of which are expressly incorporated herein by reference.
There also exist various other types of “closed loop” catheters that have inflatable balloons or fluid-expandable members that must be fully deflated prior to movement or removal of the catheter from the body. Especially in cases where the balloon or fluid-expandable member is inflatable or expandable but not elastic, it may be desirable or even necessary to apply negative pressure to the catheter lumen(s) to fully deflate the balloon or fluid-expandable member to ensure its complete collapse before moving or removing the catheter from the body.
B. Sterility Barriers for Medical Catheters:
After any catheter has been inserted into a patient's vasculature, it is sometimes desirable to further advance or reposition the catheter. If a proximal portion of the catheter has become exposed to room air and possible microbial contamination, further advancement of that portion of the catheter into the patient's vasculature may risk introduction of microbial contamination into the patient's blood. Thus, the prior art has included various apparatus and methods for creating sterility barriers to prevent contamination of patients and/or medical devices, including those apparatus and methods described in U.S. Pat. Nos. 5,385,495 (Lynn), 5,775,328 (Lowe et al.), 4,491,137 (Jingu), 4,646,772 (Silverstein et al.), 4,898,178 (Wedel), 5,341,810 (Dardel), 5,490,522 (Dardel), 5,498,230 (Adair) and PCT International Publication Nos. WO84/03034 (Drue et al.), WO97/49337 (Loxe et al.) And WO99/48424 (Lowe et al.).
Notwithstanding the prior art, there remains a need in the art for the development of new connectors for closed loop catheters to facilitate and verify complete evacuation of fluid from those catheter's closed loop fluid flow circuits and complete deflation of any expandable reservoirs (e.g., heat exchangers, balloons, etc.) formed in or on those closed loop catheters. Separately or in combination with such new connectors, there also remains a need in the art for the development of improved sterility barriers for maintaining sterility of the exteriorized portions of catheters that may be further advanced into the patient's body at a later time.